Mechanical Properties of Chemically Treated Coir and Betel Nut Fiber Reinforced Hybrid Polypropylene Composites

Abstract

Natural fiber reinforcement in polymer is one of the best ways to enhance mechanical properties of polymer. Hybrid composites provide the potential of achieving a balanced a pursuit of stiffness, strength, ductility and other mechanical properties. For this purpose coir and betel nut fiber were used as reinforcement in polypropylene matrix in present research. Raw coir and betel nut husk fiber were chemically treated with sodium hydroxide to increase adhesion of those fibers with polypropylene. Both raw and alkali treated fibers were utilized during composite preparation with the help of hot press technique. Fiber loading were varied at 5, 10 and 15 wt%, while coir and betel nut husk fiber ratios were varied at 1:1, 3:1 and 1:3. Tensile, flexural, impact, hardness and water absorption tests of prepared composites were subsequently conducted. All mechanical properties except tensile strength increased with increase in fiber loading. Properties of prepared composites were found better as compared to polypropylene matrix. Composites containing coir and betel nut at same ratio had better mechanical properties than composites containing those fibers at 1:3 and 3:1 ratio. On the other hand, sodium hydroxide treatment of raw coir and betel nut fiber increased mechanical properties of treated fiber composites as compared to raw fiber reinforced composite. Thus alkali treated 15 wt% coir and betel but fiber (at 1:1) reinforced polypropylene composite had the optimum set of mechanical properties among all prepared composites.